In new applications of LED lighting, such as street lights and automotive lights, typically a powerful light source is used. With current LEDs, this leads to a significant heat production, in the order of hundreds of watts. This heat has to be transported away from the light source, or else the light source will deteriorate. The heat is spread over a large surface of a so called heat spreader, wherefrom it can disperse into the ambient air. The heat spreader is oftentimes made of metal and may also be referred to as a heat sink.
One possible solution to the problem of transporting heat away from the light source is to use ventilator. However, the ventilator has moving parts that may break down. Further, the use of a ventilator leads to increased costs, for manufacture as well as for energy during use.
Another solution is to use heat pipes. They typically consist of a relatively stiff metal tube with a cooling fluid inside.
Still, regardless of which of these solutions is used, problems remain. When a light engine of a luminaire is exchanged, the thermal interface system is also exchanged. It is generally not possible to modify the luminaire itself. For example, it is desirable to keep the canopy of the luminaire intact. Therefore, when the light engine is exchanged, the new thermal interface system has to be adapted to the existing luminaire. This leads to increased costs for providing different types of thermal interface systems for each light engine in order to be able to use the light engine in different luminaires.
Thus, a need remains for an improved thermal interface system, which could be used in a larger number of different luminaires.